Diamond blade



FIG. 1 is a front elevational view of a diamond blade showing my new design;

FIG. 2 is a elevational plan view thereof;

FIG. 3 is a left side elevational plan view thereof;

FIG. 4 is a cross-sectional view along the A—A line; and,

FIG. 5 is a cross-sectional view along the B—B line. 

The ornamental design for a diamond blade, as shown and described. 